RAH, current is not required. I have had great reproduction success even with the 'wrong kind' of artificial spawn surfaces. The fish find a way using other structures in the pond as well.

I just noted that in the slide deck above they found benefit when current was present and in Stressless study he quoted, too much current caused them to seek shelter from the current and only use the 'sheltered' side of the spawning structure.

I was just thinking that I do have a hydrant in one area of my pond and could keep a hose running with diffuser to try to create some water movement across a spawning structure. The other structures would have to be in still water (unless I can add some electric powered underwater turbines/fans/merry-go-rounds) next to each spawning structure. I do not like the idea of electricity going to power something that lives underwater.

These dock/pier mounted deicers still make me nervous for those who might be in the water nearby.

Maybe I can use transformer and instead use 12 or 18V DC power to run a propeller/impeller/ or maybe a automobile squirrel cage type under dash heater/a/c fan to get a little water movement across the spawning disks. DC feels safer somehow...